The present invention relates to an electronic circuit device having an electronic circuit element, a substrate including a front surface on which the electronic circuit element is mounted and a reverse surface opposite to the front surface in a thickness direction of the substrate, an electrically conductive terminal member electrically connected to the electronic circuit element, a lead frame extending perpendicular to the thickness direction to face the reverse surface in the thickness direction, and a sealing resin covering at least partially the electronic circuit element, substrate and lead frame while at least a part of the electrically conductive terminal member is prevented from being covered by the sealing resin.
In a prior art electronic circuit device as disclosed by “Effect of Lead Frame Material on Plastic-Encapsulated IC Package Cracking Under Temperature Cycling” (writers: Asao Nishimura, Sueo Kawai and Gen Murakami, included by IEE TRANSACTIONS ON COMPONENTS, HYBRIDS, AND MANUFACTURING TECHNOLOGY, VOL. 12, NO. 4, pp 639-645 published in December 1989), JP-A-9-232341 and JP-A-2000-183241, an electronic circuit element and a metallic lead frame are joined with each other and encapsulated monolithically with a resin, for example, epoxy resin.